Penetration of inferior alveolar nerve canal increased by bicortical fixation after bilateral sagittal split osteotomy in mandibular prognathism.

The purpose of this three-dimensional cone beam computed tomography (CBCT) study was to identify the difference between monocortical fixation (MCF) and bicortical fixation (BCF) in mandibular canal penetration after bilateral sagittal split osteotomy (BSSO) to correct mandibular prognathism, where interosseous fixation was done by BCF or MCF. CBCT was performed 1 week postoperatively and Dolphin 3D software was used to assess direct penetration of the mandibular canal by either type of screw. The primary outcome variable was the presence or absence of mandibular canal penetration and was categorized as a binary coded variable. The BCF and MCF groups were compared by χ2 test, and the odds ratio for canal penetration was estimated. Multiple logistic regression was performed to identify factors related to canal penetration. A total of 118 patients were included. The MCF group had only 6% canal penetrations (3/50 patients) and the BCF group had 58.8% canal penetrations (40/68 patients). The regression model showed that BCF was the only factor causing mandibular canal penetration, with an adjusted odds ratio of 52.5. Awareness of the increased risk of canal penetration with BCF and potential nerve injury might influence case selection.

The impact of a surgery-first approach on oral health-related quality of life.

Orthognathic surgery using a surgery-first approach (SFA) has been shown to result in better quality of life (QoL) throughout the treatment duration; however, the effects of gender, age and type of dentofacial deformity on SFA-related QoL remain unknown. In total, 228 consecutive patients underwent SFA for correction of dentofacial deformities (skeletal class III, bimaxillary protrusion and facial asymmetry). We assessed their QoL before surgery and at 1, 6 and 12 months after surgery using the Orthognathic Quality of Life Questionnaire (OQLQ). The results indicated a significant decrease in the total OQLQ, facial aesthetics and social aspect domain scores 1, 6 and 12 months after surgery. Among all domains, the greatest improvement was noted in the facial aesthetics domain. The oral function scores declined significantly immediately after surgery, but improved significantly 6 and 12 months after surgery; however, the awareness scores remained relatively stable. At each time point, women and the bimaxillary protrusion group exhibited a significantly higher total and specific domain scores. Patients aged 18-22 years exhibited lower total and four specific domain scores than older patients. Thus, QoL improves in all aspects, except awareness domain, by 12 months after SFA, but gender, age, and type of dentofacial deformity affect this improvement.

Towards a Better Health Care Delivery System: The Tamil Nadu model.

The Tamil Nadu model of public health is renowned for its success in providing quality health services at an affordable cost especially to the rural people. Tamil Nadu is the only state with a distinctive public health cadre in the district level and also the first state to enact a Public Health Act in 1939. Tamil Nadu has gained significant ground in the various aspects of health in the last few decades largely because of the significant reforms in its health sector which dates back to 1980s which saw rigorous expansion of rural health infrastructure in the state besides deployment of thousands of multipurpose health workers as village health nurses in rural areas. Effective implementation of Universal Immunization Programme, formation of Tamil Nadu Medical Services Corporation for regulating the drug procurement and promoting generic drugs, early incorporation of indigenous system of medicine into health care service, formulation of a health policy in 2003 by the state with special emphasis on low-income, disadvantaged communities alongside efficient implementation of The Tamil Nadu Health Systems Project (TNHSP) are the major factors which contributed for the success of the state. The importance of good political commitment and leadership in the health gains of the state warrants special mention. Moreover, the economic growth of the state, improved literacy rate, gender equality, and lowered fertility rate in the last few decades and contributions from the private sector have their share in the public health success of the state. In spite of some flaws and challenges, the Tamil Nadu Model remains the prototype health care delivery system in resource-limited settings which can be emulated by other states also toward a better health care delivery system.

Antimutagenic profile of antioxidant vitamins in drosophila mulation test.

OBJECTIVE: To assess the antimutagenicity of antioxidant vitamins (vitamins A, C, and E) as expressed by their efficacy to lower aflatoxin-induced mutations. METHODS: The Muller-5 method for mutation detection was used to assay the frequency of X-chromosome linked recessive lethal mutations (XRLMs) in Drosophila. Larvae were exposed to dietary concentration of aflatoxins and/or the human therapeutic doses of any of the three antioxidant vitamins. Absence of normal eyed males among M2 progeny gave an indication of mutation induction. RESULTS: Aflatoxin supplimentation significantly increased the incidence of XRLMs in Drosophila. Mutation frequency was also raised a little above the control level in case of vitamin treatment. However, notable mitigation in mutation frequency was registered when aflatoxin-treated larvae were concomitantly fed with any of the three antioxidant vitamins. CONCLUSION: Aflatoxin exposure can enhance the frequency of gene mutation in Drosophila which is significantly lowered by each of the three antioxidant vitamins. The degree of amelioration produced by them is almost identical. This mitigation is based on the scavenging/trapping by antioxidant vitamins of DNA-reactive products (metabolites and radicals) emanating from aflatoxin metabolism.

Cytogenetic toxicity of leaf extract of Putranjiva roxburghii, a medicinal plant.

Young weaning Swiss albino mice were orally administered leaf extract of Putranjiva roxburghii at 0.5, 1.0 or 2.0 g/kg body weight/day for seven consecutive days. The results showed that the leaf extract significantly induced mitosis-disruptive chromosomal changes in bone marrow cells. No change in the incidence of structural abnormalities was, however, noticed among the metaphase chromosomes. It is proposed that the extract might have interfered with the spindle and other proteins causing polyploidy, aneuploidy, c-mitosis, etc.

Differential genotoxicity of the crude leaf extract of a medicinal plant, Casearia tomentosa.

The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division-disruptive chromosomal changes in bone marrow cells as well as in primary spermatocytes; the latter also exhibited marked increase in synaptic disruptions. A significant decrease in sperm count was noted. The incidence of structural damages in chromosomes, however, remained within the range of control level frequency. This herbal preparation, therefore, appears to be primarily spindle-poisoning in its action, but not clastogenic. The probable mechanism of this differential genotoxicity is discussed.

Crowding effects of density and personal space requirements among older people: the impact of self-control and social support.

The authors examined the effects of self-control and social support among a representative sample of 300 older people, 150 in high-density and 150 in low-density households in India. The Self-Control Schedule (M. Rosenbaum, 1980), the Comfortable Interpersonal Distance Test (M. Duke & S. Nowicki, 1972), the Social Support Questionnaire, and the Judgement of Environmental Quality Scale (I. G. Sarason, H. M. Levine, R. B. Basham, & B. R. Sarason, 1983) were the measures. A 2 x 2 x 2 (Density x Social Support x Self-Control) analysis of variance for perceptions of home environment and personal space requirements revealed that the Self-Control x Social Support interaction moderated the crowding effects of density: The participants in high-density households evaluated their home environments more positively and reduced their personal space requirements.

Prolonged murine genotoxic effects of crude extracted from neem.

Oral administration of a crude ethanol extract of the leaves of neem (Azadirachta indica A juss) to adult Swiss albino mice for 7 days at 5 mg, 10 mg or 20 mg/10 g bw/day significantly increased the incidence of structural and mitosis disruptive changes in metaphase chromosomes of bone marrow cells on days 8, 15 and 35th of observation. It is proposed that one or other of the many constituents of the extract, along with genera free radicals, interfered with DNA to yield chromosome strand breakage or produced spindle disturbances, inducing belated genotoxic effects.

Diurnal periodicity of Leishmania amastigotes in peripheral blood of Indian Kala-azar patients.

Peripheral blood smears of 20 patients with Indian Kala-azar (KA) were collected throughout the day and night and examined for presence of Leishmania amastigotes. Amastigotes were detected in 46% of peripheral blood samples taken during the day (08:00-17:00 h) and 66% and during the night (18:00-07:00 h). This difference was statistically highly significant (P < 0.0001). The confirmation of amastigote diurnal periodicity is of interest, and the high percentage of parasitemic patients at night is likely to reflect the biting habit of the sandfly vector of Kala-azar Phlebotomus argentipes.

Ameliorating effect of vitamin C on murine sperm toxicity induced by three pesticides (endosulfan, phosphamidon and mancozeb).

The ameliorating effect of vitamin C (injected intraperitoneally) was evaluated against changes in sperm count and sperm head morphology in mice fed either 3, 6 or 1000 mg/kg body wt/day endosulfan, phosphamidon or mancozeb, respectively. The animals received aqueous preparations of the pesticides and/or vitamin C once daily for 35 consecutive days. All three pesticides, irrespective of their chemical nature, significantly decreased the sperm count, as well as increased the frequency of sperm with aberrant head morphology. Out of the three doses of vitamin C used the middle and higher ones (20 and 40 mg/kg body wt/day, respectively) afforded comparatively more significant amelioration. The lower dose (10 mg/kg body wt/day) of this vitamin (quantitatively equivalent to the human therapeutic dose according to body weight) was least efficacious in both the tests. However, amelioration was never up to the control level in any case. Vitamin C doses, when administered alone, did not produce any adverse effect on sperm count and sperm head morphology.

Indian kala-azar caused by Leishmania tropica.

Kala-azar, or visceral leishmaniasis, in India is generally assumed to be a result of infection with Leishmania donovani. 15 parasite isolates collected over the past 10 years from patients with classical disease were typed by monoclonal antibodies, isoenzymes, and kDNA analysis. 4 were shown to be L tropica, a species historically associated with cutaneous disease and more recently a mild "visceralising" disease from the Desert Storm experience. The results confirm that L tropica is a co-endemic agent of visceral leishmaniasis in India, and may shed light on the rising frequency of therapeutic unresponsiveness to sodium antimony gluconate, which complicates treatment of this lethal disease.

Perception of crowding among children and adolescents.

The effects of spatial orientation (closed vs. open) and furniture arrangement (side vs. central) on Indian children's (6 to 8 years) and adolescents' (16 to 18 years) perceptions of crowding were studied, using Desor's (1972) Crowding Perception Test. The results indicated that spatial orientation and furniture arrangement had different effects on children's and adolescents' perceptions of crowding. The children perceived less crowding than the adolescents did, and central furniture arrangement was perceived as more crowded than side furniture arrangement was.

Cytogenetic toxicity and no-effect limit dose of pesticides.

The no-effect limit dose (NELD) of three commonly used pesticides with respect to their cytogenetic toxicity was determined in a number of test systems using a sufficient number of lower doses to characterize the dose-effect relationship. For lindane, malathion and metacid, this dose was 3.2, 7.0 and 3.0 mg/litre, respectively, for mitosis inhibition and 9.0, 55 and 60 mg/litre, respectively, for chromosome clastogeny in onion root-tip cells. For chromosome clastogeny in mice bone marrow cells, the NELDs of the three pesticides were 1.6, 1.5 and 2.0 mg/kg body weight/day, respectively. These values for dominant lethals and X-chromosome-linked recessive lethals in Drosophila were 20 and 5 micrograms lindane/litre, 2 and 3.5 micrograms malathion/litre and 4 and 5.5 micrograms metacid/litre, respectively. Thus, the NELDs are not only pesticide specific but also organism specific, tissue specific and even damage specific. Furthermore, the NELD values determined are so small that the real human exposure to pesticides cannot be reduced below these levels without compromising the effectiveness of pesticides in use.

Modulation of ochratoxin-produced genotoxicity in mice by vitamin C.

Ochratoxin A (OA), when administered orally daily for 45 days to albino Swiss mice, Mus musculus, at a level equivalent to the human dietary concentration of 1 microgram/kg body weight/day, increased the production of abnormalities in both mitotic and meiotic chromosomes as well as in the gross morphology of the sperm head. The sperm count per unit volume of caput epididymal suspension also decreased. Vitamin C at a concentration equivalent to the human therapeutic dose (10 mg/kg body weight/day), when administered orally concurrently with OA, significantly minimized the incidence of these abnormalities. The protective effect of vitamin C was most marked in mitotic chromosomes followed by that in meiotic chromosomes and sperm head morphology; the improvement in sperm count was least marked. The possible mechanism of this effect is discussed.

Effect of retinol on ochratoxin-produced genotoxicity in mice.

Ochratoxin (1 microgram/kg body weight/day), when administered orally daily to albino Swiss mice for 14 continuous days, increased the incidence of abnormalities in mitotic and meiotic metaphase chromosomes, and the gross morphology of the sperm head; the sperm count per unit volume of caput epididymal suspension also decreased. These genotoxic effects were substantially reduced by concurrent oral administration of retinol at double the clinically therapeutic dose. It is possible that the electrophilic metabolites of ochratoxin form adducts with DNA or produce replacement-type mutations. Retinol may achieve its antigenotoxic effect by means of blocks and shunts in the ochratoxin metabolic pathway. Vitamin A-mediated cellular repair and scavenging of the mutagenic radicals can also take place. The vitamin itself has some genotoxic potential.

Vitamin A ameliorates the genotoxicity in mice of aflatoxin B1-containing Aspergillus flavus infested food.

Young weaning Swiss albino mice were orally administered crude aflatoxin B1 in a dose mimicking human exposure condition, i.e. at 0.05 micrograms/kg body weight/day for 14 weeks. Vitamin A (retinol) was orally administered along with the toxin in double (132 IU/kg body wt/day) the human equivalent therapeutic dose. The results suggested that vitamin A minimised the frequency of toxin-induced clastogeny in both mitotic and meiotic chromosomes. The decreases in sperm count as well as increases in abnormality in the gross morphology of the sperm-head, as observed upon toxin treatment, was ameliorated by the vitamin A.

Impact of higher doses of vitamin C in modulating pesticide genotoxicity.

The modulatory effect of higher doses of vitamin C (ascorbic acid) on the genotoxicity of the three pesticides (endosulfan, phosphamidon, and mancozeb) was assessed in the in vivo micronucleus test in Swiss albino mice. Concurrent administration of the vitamin in a dose (20 mg/kg bwt/day) equivalent to double the human therapeutic one, along with each of the three pesticides, was most effective as an antimutagen. The therapeutic dose (10 mg/kg bwt/day) was comparatively less so, and the quadruple (40 mg/kg bwt/day) of it did not show any further amelioration.

Vitamin C mediated amelioration of pesticide genotoxicity in murine spermatocytes.

The effect of vitamin C on the genotoxicity of three pesticides (Endosulfan, Phosphamidon, Mancozeb) was monitored by screening meiotic (metaphase I) chromosomes in the primary spermatocytes of Swiss albino mice, Mus musculus. A dose-dependent amelioration by vitamin C was observed in the Phosphamidon-treated group where quadruple the therapeutic dose produced maximum amelioration. In Endosulfan- and Mancozeb-treated groups, no further amelioration was achieved beyond the double dose of vitamin C, and the damage frequency did not come down to the control level. The possible mechanism of this effect is discussed.